Low-temperature Hall effect in electron-doped superconductingLa2−xCexCuO4thin films

Abstract

We investigate the low-temperature Hall effect in electron-doped ${\text{La}}_{2\ensuremath{-}x}{\text{Ce}}_{x}{\text{CuO}}_{4}$ thin films from heavily underdoped $x=0.06$ to heavily overdoped $x=0.17$. With increasing $x$, the charge carriers that dominate the Hall effect gradually change from electronlike to holelike. From the Hall coefficient and differential Hall coefficient, we infer that a large holelike Fermi surface forms above $x=0.15$, that is, the electronlike pocket may exist until $x=0.15$. Meanwhile, the sign of the Hall resistivity changes from negative $(x=0.105)$ to positive $(x=0.12)$ at 2 K, indicating that single electron pocket exists below $x=0.105$ at low temperature.